Grinding machine



Filed March 26, 1931 3 Sheets-Sheet 1 May 29, 1934. R. H. CRAMER'GRINDING MACHINE 3' Sheets-Shet 2 Filed March 26 .1951

Patented May 29, 1934 PATENT OFFICE GRINDING MACHINE Raymond B. Cramer,Newark, N. J., assignor to General Motors Corporation, Detroit, Mich, acorporation of Delaware Application March 26, 1931, Serial No. 525,374

35 Claims.

This invention relates to grinding machines and comprises all thefeatures of novelty herein disclosed. An object of the invention is toprovide an improved machine for automatically grinding a series ofcircular articles to a predetermined diameter.- Another object is toprovide an improved internal grinding machine. Another object is toprovide improved mechanism for feeding articles to a grinding machine,more especially an internal grinding machine of the chuckless type.Still another object is to provide an improved chuckless grindingmachine.

To these ends and also to improve generally upon machines of thischaracter, the invention consists in the various-matters hereinafterdescribed and claimed. In its broader aspects, the

invention is not necessarily limited to the speciflc constructionselected for illustrative purposes in the accompanying drawings in whichFig. 1 is a perspective view of the machine with some parts broken away.

Fig. 2 is a plan view.

Fig. 3 is an end view with some parts omitted and some in section.

A work-piece W, such as a sleeve to be internally ground, is supportedand rotated by a series of wheels, one wheel 2 being driven by a beltpulley 3 to control rotation .of the work. The wheel shaft is journalledin a head 4 bolted to a base plate 6 rigidly mounted on a bridge 8attached to a main frame. The frame slidably supports a table orcarriage 10 which reciprocates horizontally below the bridge. Thecarriage supports a grinding wheel G which enters the bore of. the

work-piece W and has any suitable cross feeding means (not shown) tofeed the wheel directly towards the backing or control wheel 2. Alateral.

extension of the base plate 6 is provided with inclined ways 12 for aslide 14 which rotatably carries a work-supporting idler wheel 16.Upwardly projecting lugs 18 on the head 4 support a rock shaft 20carrying a bracket 22 clamped to the shaft by a clamping screw 24.. Thebracket is split and provided with a clamping screw 26 to adjustablysupport an arm 28 which is forked at 'bolted to one end of the carriage10. Whenever 65 the carriage retreats to the right to a retractedposition to carry the grinding wheel out of the work, at the conclusionof grinding, the cam 48 engages the cam roller 46 and lifts the rod 38.This rocks the shaft 20 and lifts the pressure idler wheel 30 from thework a sufilcient distance to allow a new piece to roll in between thepressure wheel and .the supporting idler wheel 16. The ball 42 permitsthe lifting rod to have a slight tilting movement without cramping.

The front of the base plate 6 has guide lugs 60 one of which has a keyfor a sliding shaft 62. The shaft is pressed in one direction by a coilspring'64 interposed between one of the guide lugs 60 and a collar 66 onthe shaft. Two collars 68 are pinned to the shaft on vopposite sides ofa bracket '70 which has a limited rocking movement on the shaft. Rockingis limited by a pin 72 entering an arcuate slot in the bracket from oneof the collars 68. A' slotted arm '74 is adjustably secured to thebracket '70 by a clamping screw 76. The arm projects rearwardly, itsmiddle portion having a hollow boss or enlargement 78 from whichprojects a gauge supporting extension '80. The extension is fastened atits rear end to a vertical bracket 82 having a screw 84 for verticallyadjusting a gauge housing 86. Projecting laterally from the bracket 82is a gauge-supporting feeler 88 which rests on the inner wall of thework-piece W. The feeler supports the gauge on the work in a floatingmanner, the entire gauge mechanism being free for a slight angularmovement with the arm around a center at the sliding shaft 62. Theangular move ment permits the feeler to be lifted from the work orlowered against it, as will appear, while the sliding of the shaft 62permits the feeler to be Withdrawn from the work. These movementsprecede ejection of the work.

Diametrically opposite the gauge supporting feeler 88 is an upper feeler90 having a vertical slide bar 91 slidable in the gauge housing, therelative movement of the two feelers being shown by an indicator 92.The'movement of the feeler 90 also controls successively a number ofelectric circuits not essential to the present invention. It

is sufficient to note that the first circuits may control an increase inthe stroke of the carriage to traverse the grinding wheel across adressing tool or diamond, the final circuit controlling the retreat ofthe carriage to a retracted position at the conclusion of grinding. Suchcarriage movements are now well known in the art of internal grinding.

Pivot-ed to the front of the gauge housing at 94 is alever 96 having itsshorter arm overlying a stud 98 which projects through a slot in thegauge housing from the vertical slide bar 91. The longer arm of thelever carries a pin 100 which projects loosely into a slot 102 in an arm104 fastened to the upper 'end of a vertical plunger 106. The plunger isguided vertically in an opening of the base plate and carries a cam roll110 arranged in the path of a cam 112 formed on the above described camplate 50 in advance of the cam 48 and having a shorter incline than thecam 48. When the carriage retreats at the conclusion of grinding, thecam 112 engages the cam roller 110 and lifts the plunger 106. The lever96 is thereby rocked clockwise, depressing the stud 98 and the upperfeeler 90 to free the latterfrom the work: then, when the stud 98reaches the .bottom of its slot, the lever is locked against swingingand is lifted bodily and with it the gauge housing and the lower feeler88. Next comes a sliding of the gauge mechanism to the left and awayfrom the work.

The slidable shaft 62 has a slot 120 at one end in which is journalled acam roller 122. A tapered cam surface 124 on a vertical plunger 126 isarranged to engage the roller and move the shaft to the left. Theplunger 126 is guided in aligned openings of the base plate and bridgeand carries a cam roller 130 in the path of a cam 132 fastened in agroove of the extension 56. The cam is set a greater distance from itsplunger than the cam 12 so that, after the feelers are separated, theshaft 62 will be forced to the left a short distance to move the gaugemechanism away from the work. The pressure idler wheel 30 is lifted asabove described after, or simultaneously with, the separation of thefeelers and the machine is then ready to eject the work and receive anew piece.

As the carriage retreats, an ejector finger 140 is pushed against thework and slides it endwise from the supporting wheels into an inclineddischarge chute 142 down which the finished piece rolls to the frontofthe machine. The ejector finger projects rearwardl'y between thefeelers, its front end carrying a stop bar 144 which momentarily arrestsan incoming piece. The finger 140 is slotted and adjustably secured by aset screw 148 to the end of an ejector rod 150 which is guided in thehollow boss or enlargement '78 and is normally urged to a retractedposition by a coil spring 152 attached to a bent stud 154 on the baseplate 6. A clamping block 156 is fastened in adjusted position on therod 150 by a set screw and has a hollow casing 158 housing a catchpin-160 which is pressed down by a coil spring 162 engag-' ing a collaron the pin. A finger 164 projects rearwardly from a long rod 166 whichis adjustabl'y clamped in a sleeve 168 on a standard 1'70 rising fromthe carriage extension 56. When the carriage retreats to the right, thefinger 164 picks up or engages the catch pin 160 and slides the ejectorrod 150 to operate the ejector finger. The ejector is released when acam 1'72 on the bent upper end of the catch pin strikes a stud 1'74 onthe enlargement '78. This lifts the catch pin so that it is free to rideback over the finger 164 when the coil spring 152 retracts the ejectorrod. When the table returns, the finger 164 engages an incline on thecatch pin to get beyond the latter. A short coil spring 176 cushions theejector finger 140.

An inclined entrance chute 180 has its rear end slotted and arrangedsubstantially tangentially with respect to the supporting idler wheel 16so that the work will roll freely down the chute and over the wheel 16into contact with the control wheel 2 when the pressure idler wheel 30is lifted. Such rolling piece is temporarily arrested, however, by thestop/bar 144 when the ejector is advanced to slide a finished piece intothe discharge chute. The entrance chute has the front end 184 of itsbottom wall bent upwardly into a groove in the front side wall 186 of aV bottom feed chute which extends horizontally, in an elevated position,at the front of the machine. The entrance chute 180 has a side wall 188whose front end is bent laterally and extended into a groove of the rearside wall 190 of the feed chute. Another side wall 192 of the entrancechute is formed by an angle iron adjustably mounted on the bottom wall.Work-pieces are guided in endto-end relation by the feed chute which issupported in elevated position by angle brackets 194 on the front of themachine. The feed chute has its middle portion cut away in the isometricview to reveal the mechanism beyond and below it.

At its left end. the feed chute has a depending lug 196 bored to guide afeed rod 198 which has a second sliding support in an opening in one ofthe angle brackets 194. A pair of spaced nuts 202 are threaded on thefeed rod to secure in adjusted position a vertically slotted pusher bar204 which pushes the work-pieces along the feed chute from a piled-upposition in a magazine 205. Acoil spring 206, interposed between one ofthe angle brackets 194 and one of the nuts 202, presses the pusher barto retracted position, the bar being guided in a narrow slot 208 at thebottom of the feed chute. The pusher bar is advanced from a position atthe left of the magazine to a position beneath it. This pushes thelowermost piece from the magazine, the remaining pieces being supportedby a concave seat 210 at the top of the pusher bar. In the isometricview, the bar is shown out of position with respect to its operatingmeans to illustrate its sup- 125 porting function af-ter'advance.Advance is effected during the retreat of the carriage, a bent bracket212 on the left end of the carriage extension 56 supporting a screw 214which strikes the outer end of the feed rod 198.

The magazine 205 comprises a U-shaped plate 216 connected to verticalangle irons 218 which are supported on the feed chute. The U-shapedplate 216 encloses three sides of the magazine, the remaining side beingclosed by a vertically adjustable gate 220 guided by a'pair of innerangle irons 222 and by recessed cross bars 224 which connect two of thesupporting angle irons 218. Vertical adjustment of thegate 220 and ofthe pusher bar adapt the feeder for work of 40 different diameters. Themagazine "also has a contractible lining composed of side plates 226pivoted at the top to hinge pins 228, the approach of'the lower ends ofthe side plates adapting the magazine for smaller work.

Assuming a work-piece is in grinding position on the supporting wheels,the carriage 10 has a short reciprocation sufficient to traverse thegrinding wheel G along the bore of the work, the wheel G having also theusual intermittent 150 cross feeding movement towards the control wheel2. As the work approaches size, as determined by the gauge, the grindingwheel has one or more limited withdrawals to dress it against a diamondand then returns to finish the piece. When the piece reaches final size,the grinding wheel and carriage retreat to a greater distance undergauge control. In this final retreat, the cam 112 comes into action onthe plunger 106. The upper feeler 90 is depressed and the lower feeler88 is elevated to clear the work. Cam 132 operates its plunger 126 toslide the shaft 62 and move the gauge feelers out of the-work. Cam48'also operates its plunger 44 to lift the pressure idler wheel. Thefinger 164 engages the catch pin 160 and operates the ejector to pushthe finished piece into the discharge chute. The screw 214 operates thepusher bar 204 which slides the line of work-pieces in the feed chute todeliver one of them from the feed chute into the inclined entrance chute180. The new piece rolls down against the stop bar 144 and istemporarily arrested until the stud 174 tripsv the catch pin 160 to letthe coil spring 152 retract the ejector. The new piece then rolls downto grinding position and the carriage returns to the left to begingrinding. As the carriage returns, the various cams are withdrawn sothat the pressure idler wheel comes down, the gauge feelers enter thework and separate and the pusher bar is retracted from under themagazine to let the stack of pieces descend against the feed chute.

I claim:

1. In an internal grinding machine, a grinding wheel, a backing wheel, awork-supporting wheel, means for automatically feeding work of roundsection into grinding relation to the wheels means for holding the workfrom axial movement during grinding, and means for automatically movingthe finished work out of grinding relation to the wheels; substantiallyas described.

2. In an internal grinding machine, a grinding wheel, a backing wheelopposing the grinding wheel, a work-supporting wheel, and an inclinedchute arranged to guide articles of round section into supportedengagement with the backing wheel and the work-supporting wheel, thechute sloping downwardly and substantially meeting the supporting wheelin tangential relation thereto; substantially as described.

3. In an internal grinding machine, a grinding wheel, a backing wheel, awork-supporting wheel, means for guiding articles of round sectionsubstantially tangentially of the work-supporting wheel and transverselyof its axis, and means for ejecting the articles axiallyof the wheels;substantially as described.

4. In an internal grindingmachine, a grinding wheel, a backing wheel, awork-supporting wheel, an inclined entrance chute arrangedsubstantially. tangent to the supporting wheel, and an inclineddischarge chute at one end of the supporting wheel; substantially asdescribed.

5. In an internal grinding machine, a grinding wheel, a backing wheel asupporting wheel, an

inclined entrance chute arranged substantially tangent to the supportingwheel, an inclined discharge chute at one end of the supporting wheel,

and means for moving a Work-piece axially from the supporting wheel tothedischarge chute; substantially as described.

6. In an internal grinding machine, a grinding wheel, a backing wheel, awork-supporting wheel, a pressure wheel for holding work of roundsection in operative relation to the other wheels, means for moving thepressure wheel bodily towards and from the work-supporting wheel, andautomatic means for introducing a work-piece to grinding position intimed relation to the movement of the pressure wheel away from thework-supporting wheel; substantially as described.

'7. In an internal grinding machine, a grinding wheel, a backing wheel,a work-supporting wheel, a pressure wheel for holding work of roundsection in operative relation to the other wheels, means for moving thepressure wheel bodily towards and from the work-supporting wheel, and aninclined entrance chute sloping downwardly towards the work-supportingwheel and substantially meeting the latter for guiding work-piecesbetween the work supporting wheel and the pressure wheel; substantiallyas described.

8. In an.inte rnal grinding machine, a grinding wheel, a backing wheel,a work-supporting member spaced from the backing Wheel and having itsWork engaging portion lower than the work engaging portion of thebacking wheel, and

' scribed.

9. In an internal grinding machine, a grinding wheel, a backing wheel, awork-supporting member spaced from the backing wheel and having its workengaging portion lower than the work.

engaging portion of the backing wheel, a pressure wheel for holding workof round section against the backing wheel and the work-supportingmember, -means for moving the pressure wheel towards and from thework-supporting member, and means for introducing a work-piece betweenthe pressure wheel and the work-supporting member when said pressurewheel is moved away from the supporting member; substantially asdescribed. 1

10. In an internalgrinding machine, a grinding wheel, a work-head, acarriage for one of said members to cause the grinding wheel to occupythe interior of a hollow work-piece, a gauge having a feeler, means forcausing the feeler to enter the work-piece from the end opposite to thegrinding wheel, and mechanism for moving said feeler radially of thework-piece into and out of contact with the inner wall thereof;substantially as described.

11. In an internal grinding machine, a grinding wheel, a work-head, acarriage for one of said members to cause the grinding wheel to occupythe interior of a hollow work-piece, a gauge having a feeler enteringthe work-piece from the end opposite to the grinding wheel, andmechanism for moving the feeler both radially and axially of thework-piece; substantially as described.

12. In an internal grinding machine, a grinding wheel, a work-head, acarriage for one of saidmembers to cause the grinding wheel to 'occupythe interior of a hollow work-piece, a gauge hav ing a feelerentering-the work-piece from the end opposite to the grinding wheel, andmechanism controlled by the movement of the carriage for successivelycausing a radial and an axial shifting movement of the feeler withrespect to the ing a pair of opposed feelers entering the workpiece andriding on the inner wall thereof, one of said feelers being movable withrespect to the other in response to change in size of the workpiece, andmechanism for causing the feelers to approach each other to. clear theinner wall of the work-piece; substantially as described.

14. In an internal grinding machine, a grind-' ing wheel, a work-head, acarriage for one of said members to cause the grinding wheel to occupythe interior of a hollow work-piece, a gauge having a pair of opposedfeelers entering the work-piece and riding on the inner wall thereof,one of said feelers being movable with respect to the other in responseto change in size of the Work-piece, and mechanism for causing thefeelers to move out of the work-piece axially thereoif; substantially asdescribed.

15. In an internal grinding machine, a grinding wheel, a work-head, acarriage for one of said members to cause the grinding wheel to occupythe interior of a hollow work-piece, a gauge having a pair of opposedfeelers entering the workwithdraw from the inner wall of the. work-pieceand move axially out of the work piece; substantially as described.

16. In an internal grinding machine, a grinding wheel, a work-head, acarriage for one of said members to cause the grinding wheel topccupythe interior of a hollow work-piece, a gauge having a feeler to enterthe work-piece and ride on the inner wall thereof, means for moving the"ing wheel, a work-head, a carriage for one of said feeler out of thework-piece, and mechanism for expelling the work-piece and introducing anew work-piece to the work-head when said feeler is withdrawn;substantially as described.

17. In an internal grinding machine, a grinding wheel, a work-head, acarriage for one of said members to cause thegrinding wheel to occupythe interior of ahollow work-piece, a gauge having a feeler to enter thework-piece and ride on the inner wall thereof, means for moving thefeeler into and out of the work-piece, and mechanism for inserting thework-piece laterally of the work-head when the feeler is withdrawn;substantially as described.

18. In an internal grinding machine, a grinding wheel, a work-head, acarriage for one of said members to cause the grinding wheel to occupytheinterior of a hollow work-piece, a gauge having a feeler to enter thework-piece and ride on the inner wall thereof, means for moving thefeeler out of the work-piece when the grinding wheel and wprk-piece areaxially separated, and means for introducing the work-piece laterally tothe work-head between the grinding wheel and the feeler; substantiallyas described.

19. In an internal grinding machine, a grinding wheel, a work-head, acarriage for one of said members to cause the grinding wheel to cocupythe interior of a hollow workpiece or to be disposed beyond the endthereof, the work-head comprising a plurality of wheels, means formoving one of the wheels to engage or to release the work, a gaugehaving a feeler movable towards and from the work-head to enter andleave the work-piece, and means for introducing a workpiece laterally tothe work-head when the grinding wheel, feeler and work-head wheels arein their separated relations; substantally as described. 1

20. In an internal grinding machine, a grinding wheel, a work-head, agauge having a pair of opposed feelers to enter a hollow work-piece, anejector extending between said feelers and across one end of thework-piece, and means for actuating the ejector to remove the work-piecefrom the work head; substantially as described.

21. In an internal grinding machine, a grinding wheel, a work-head, agauge having a feeler to entera hollow work-piece, a support for thegauge, an ejector at one end of the work-piece, and a rod'carried by thegauge support for actuating the ejector; substantially as described.

22. In an internal grinding machine,a grinding wheel, a work-head, acarriage for one of said members to cause the grinding wheel to occupythe interior of a hollow work-piece, the work-head comprising a backingwheel and a work-supporting wheel, an ejector at one end of theworkpiece, and mechanism for actuating said ejector to slide thework-piece axially along the wheels of the work-head to a positionbeyond the end thereof; substantially as described.

23. In an internal-grinding machine, a grinding wheel, a work-head, acarriage for one of said members to cause the grinding wheel to 00--cupy the interior of a hollow work-piece, the work-head comprising abacking wheel and a work-supporting wheel, an ejector at one end of thework-piece, and mechanism controlled by the movement of the carriage foroperating the ejector to slide the work-piece axially along the wheelsof the work head; substantially as described. '-.'1

24. In an internal grinding machine, a grindmembers to cause thegrinding wheel to occupy the interior of a hollow work-piece, theworkhead comprising a plurality of supporting wheels, anejector at oneend of the work-piece, means for operating the ejector to slide thework-piece axially from the supporting wheels, and a bar carried by theejector to postpone the insertion of a new work-piece; substantially asdescribed.

25. In an internal grinding machine, a grinding wheel, a work-head, acarriage for one of said members to cause the grinding wheel to occupythe interior of a hollow work-piece, the workhead comprising a pluralityof wheels, a chute leading to the work-head wheels, an ejector at oneend of the work-piece, means for operating the ejector to slide thework-piece axially from thework-head wheels, and a bar carried by theejector to arrest a new work-piece in the chute; substantially asdescribed.

26; In a grinding machine, a grinding wheel, a work-head having aswingable work-engaging wheel, and mechanism forswinging the wheel andcomprising an arm and a plunger, and a ball tially as described.

. 28. In a grinding machine, a grinding wheel, a

work-head having a pair of work-supporting wheels, a pressure wheelmovable towards and from the others, an ejector to slide a work-pieceaxially along the work supporting wheels, and the pressure wheel beingflanged to hold the work-piece from such axial movement during grinding;substantially as described.

29. In a grinding machine, a grinding wheel, a work-head having workengaging wheels, an inclined chute leading downwardly to said wheels toconduct work-pieces thereto, a feed chute, and a pusher for advancingwork-pieces along said feed chute to the inclined chute; substantiallyas described.

' 30. In a grinding machine, a grinding wheel, a backing wheel, awork-supporting wheel, mechanism for automatically feeding articles ofround section successively into operative relation to said wheels for agrinding operation and for ejecting the articles after the grindingoperation, and mechanism for causing the grinding wheel and the otherwheels to be separated during the feeding and ejecting operations;substantially as described.

31. In an internal grinding machine, a grinding wheel; a backing wheelopposing the pressure of the grinding wheel, a work-supporting memher,and automatic mechanism for feeding work of round section transverselyover the work-sup porting member and substantially radially against theperiphery of the backing wheel; substantially as described.

32. In an internal grinding machine, a, grinding wheel, a backing wheelopposingrth'e pressure of the grinding wheel, a work-supporting member,means for -feeding work of round section transversely over thework-supporting" member and against the periphery of the backing wheel,and means for holding the work against axial movement during grinding;substantially as de- 1 scribed.

33. In an internal grinding machine, a grinding wheel, a backing wheel,a work-supporting member, means for feeding work of round sectiontransversely over the work-supporting member and against the peripheryof the backing wheel, and means for ejecting the work lengthwise of thesupporting member; substantially as described.

351. In an internal grinding machine, a grinding wheel, awork-head, acarriage for one of said members to cause the grinding wheel to occupythe interior of a hollow work-piece, a gauge having a feeler, mechanismfor causing relative axial shifting movement between the feeler and thework-piece to cause the feeler to occupy the bore of the work-piece, andmeans for thereafter causing relative radial movement between the feelerand the work-piece to cause the feeler' to contact with the wall of thebore; substantially as de-

